This paper presents (1) positive and negative effects about bio-diesel fuels (BDF) promotion policies in Germany, (2) analytical result of German diesel fuel demand curve, especially price elasticity, and (3) German BDF price determination factor. We can conclude the following three points. (1) Energy tax exemption stimulates huge BDF production, while causing serious tax revenue shortage. (2) Demand price elasticity of diesel fuel is much less than that of gasoline, thus it seems that German ecological-tax reform has not restrained diesel demand. (3) BDF price once correlated with diesel price from 1999 to 2004. But it has been determined by feedstock (rapeseeds) price since 2005.
The apparent viscosity of pulverized chicken manure with suspended activated carbon, which is the feedstock for the supercritical water gasification, was determined using a rotary viscometer at 20, 30, 40°C with activated carbon weight fraction ranging from 0.0 to 0.20. No precipitation was observed in the pulverized chicken manure after one hour whether activated carbon is added or not. The chicken manure slurry behaved as non-Newtonian, thixotropic fluid. Apparent viscosity of the slurry decreased with an increase in temperature, and increased as the weight fraction of the activated carbon increased. A correlation to predict the apparent viscosity as a function of temperature and activated carbon weight fraction was determined. Validity of the Einstein's viscosity formula was certified under a constant shear stress condition in terms of the effect of activated carbon addition. The error in Einstein's formula was larger when activated carbon concentration was higher.
The purpose of this study is to evaluate impact assessment of regional characteristics and some measures to reduce green house gas in waste disposal systems. For that purpose, we developed a linear optimization model that evaluates three waste disposal systems such as landfill, incineration and ash melting. Also, we assumed that LFG recovery power generation, and the incineration system and the ash melting system can be combined with the electric power generation. In addition we evaluated the effect of CDM that is considered as a measure to reduce GHG emissions in the local city in China. The results obtained in this study are as follows. (1) In Tokyo, where the maximum landfill area is restricted, the waste disposal system is incineration and will change to ash melting. In China, where the maximum landfill area is larger than that in Tokyo, the waste disposal system is landfill and will change to incineration. (2) The electric power charge is an important factor to use LFG to generate electricity efficiently in developing countries where the waste disposal system is landfill. (3) In developing countries, if GHG credit is approved, LFG leakage decreases and the amount of LFG power generation increases.
The behavior of glucose under hydrothermal conditions is of great interest in the development of processes for supercritical water gasification and the hydrothermal pretreatment of lignocellulosics. Our group examined this behavior in a series of glucose decomposition experiments in water at a pressure of 25 MPa in the temperature range of 448-498 K. The rate parameters of the reactions from glucose to the decomposition products were determined by the least squares method. The reaction order of unity for glucose decomposition was found to be the result of several reactions of various reaction orders proceeding in parallel. The reaction orders for the decompositions of fructose, erythrose, glyceraldehyde, and 1,6-anhydroglucose can be considered unity without large error. By examining the selectivity of glucose conversion reactions, we determined that almost all of the glucose was initially converted into fructose, but at 498 K, 1,6-anhydroglucose and erythrose selectivity matched that of fructose. The kinetic parameters determined in our experiments should be useful for predicting the reaction taking place in the pre-heating section of the supercritical water gasification process and in the hydrothermal pretreatment reactor used for the saccharification of cellulosic materials.
Dry gas cleaning was performed using five different commercial activated carbons (ACs) at 150-300°C. Phenol, o-cresol, naphthalene, and 1-methylnaphthalene were employed as the tar model compounds that produced from biomass gasification. The effect of the adsorption temperature and physical characteristics of ACs on the adsorption behaviors such as the breakthrough curves and adsorption capacities was investigated using a fixed-bed reactor. At 150°C, o-cresol and naphthalene were effectively removed; the adsorption capacities of the ACs were 13.4-19.4g-tar/(100g-AC) and 19.9-23.7g-tar/(100g-AC) in o-cresol and naphthalene, respectively. For effective tar removal, a larger surface area, a smaller average particle size, and an appropriate pore diameter were necessary. The effect of the tar model compounds on the adsorption behavior was investigated using the same AC at 150°C. The adsorption capacity was found to be 10.5-32.6g-tar/(100g-AC) in the following order : phenol<o-cresol<naphthalene<1-methylnaphthalene. Tar compounds having methyl groups (o-cresol and 1-methylnaphthalene) were removed more effectively as compared to those having no methyl groups (phenol and naphthalene).
Characteristics of decomposition and saccharification of various lignocellulosic biomass were investigated with a percolator type reactor under hydrothermal conditions with three-step heating (30°C, 130°C and 200°C) for fractionation of components in the biomass. Herbaceous biomass (rice straw, barley straw) showed high solubilized products yield in the each fraction in comparison with woody biomass (eucalyptus, douglas fir and Japanese cedar). The solubilized products obtained at 280°C were mainly the hemicellulose-derived monomers and oligomers. The main component of hydrothermal treatment residue was cellulose. Particularly, in case of herbaceous biomass, the ratio of cellulose in the residue reached about 80%. This is because of lignin in the herbaceous biomass was easy to solubilize in comparison with that in woody biomass. The recovered hydrothermal-residues were treated with cellulase. In case of cellulose in the herbaceous biomass-residue was converted into glucose at 60% yield. On the other hand, in case of woody biomass, the residue was hardly converted into glucose. Japanese cedar-residue was treated at 280°C. The solubilized products were treated with cellulase. As a result, cellulose in the Japanese cedar was converted into hexose (glucose+fructose) at 60% yield.
Utilization of woody biomass represents an effective alternative to fossil fuels for mitigation of global warming. The purpose of the study is to design woody biomass energy system, and to analyze the effect on the total cost of the energy system and environmental impact derived by installing biomass power plant in rural area in Japan. The energy system consists of woody biomass, logistics, energy conversion, and distribution of both electricity and heat. In order to analyze the comprehensive network of the system, an energy-economic model is developed and applied for the rural area. The model considers the balance between energy conversion sectors and energy demand sectors in long-term taking into account the cost of biomass power generation, price of conventional energy, legal issues, and limits of quantity of biomass supplied in target area. In addition to the feature mentioned above, the energy-economic model derives the cost minimum configuration of the energy system because an open market is supposed in the energy model. As the conversion technology of biomass, direct combustion power plant, and gasified power plant are set in the energy conversion part in the woody biomass energy system; the economic and technological performance of the biomass power plants is evaluated circumstantially. A major issue of preventing woody biomass from the smooth installation is the high cost of biomass resource. Hence, the subsidy is supposed for decreasing the cost of woody biomass in the study, and the effect of the subsidy on the total cost and amount of woody biomass used in the energy system are also evaluated.
Properties of wood powder pulverized by a vibration were evaluated. In the previous paper, it was clarified that the wood biomass was able to be pulverized into micron order particle by a vibration mill equipped with rods and balls. In this paper, characteristics of wood powder, such as particle diameter, particle shape, aspect ratio, specific surface area, crystallnity and equilibrium moisture content, was measured. As the results, it was found that the vibration mill was available for the production of wood powder, which has big surface area and low crystallnity.
Presently disposition of biomass resources such as thinning materials of forest and scrap wood have a big problem. We have proposed to use as charcoal by carbonizing these biomass resources. This charcoal must be useful, because of valuation of carbonization cost. Her are shown for a few value-added charcoal from biomass resource. These carbons named “Biocarbon” 1. The charcoal which has a lot of pore, compared with a traditional charcoal is produced from used paper. This charcoal is used for a flowerbed or a seedbed. These flowerbed and seedbed can grow plant and seed without any soil. 2. The high density charcoal is produced from sawdust. This high density charcoal is substituted into coke from coal and used in the Melting Process for waste. 3. The charcoal board is produced from charcoal powder and used as construction materials. The charcoal board can adsorb formaldehyde for a long time. Because we found this adsorbed formaldehyde reacts to formic acid. The fireproof charcoal board is also produced by mixing slaked lime.
In the past decade, much research has been focused on electroactive polymers (EAPs) as actuators. However, less well known is the fact that some of these materials have outstanding performance in the generator mode. Whereas polymer actuators convert electrical energy to mechanical energy, polymer generators convert mechanical energy to electrical energy. Many of the characteristics that make EAPs attractive as actuators also make them attractive as generators. Potential advantages include high energy output per unit mass, low cost, good coupling to many mechanical inputs, lightweight materials, and flexible design. We believe that given new capabilities enabled by EAPs, and the world's critical need for electrical power, that EAP power generation is an important focus area for research and development. Indeed, it is possible that EAP power generation could well exceed the importance of EAP actuators, itself an exciting technology area.